Light-metal piston, especially for use in connection with internalcombustion engines



June 9, 1925.

- P. SCHUTTLER ET AL LIGHT METAL PISTON, ESPECIALLY FOR USE INCONNECTION WITH INTERNAL COMBUSTION ENGINES Filed Jan. 26, 1925 m I n LW P E s INVENTORJ ATTORNEY.

Patented June 9, 1925.

PAUL scnnr'rnea AND ibrarian, or crfran to'rivnn GERMANY.

,I RG, time seems LIGHTMETAL emoir, risieacrannv sea use In connectionwarn mrnnjnhnooraleosrron ENGINES.

Application and anal-y 26, 825. semi No. 4,113.

To all whom it may concern Be it known that we, PAULYSOHflTTLER andSTEPHAN Lornnnn, citizens :of the German Republic, and residents,respectively, of

85 VVilmcrsdorferstrasse, Charlottenburg,

near Berlin, Germany, and of 6 l/Vitzlebenplatz, Charlottenburg, nearBerlin. Ger

many, have invented a new and useful Improved Light-Metal Piston,Especially for Use in Connection with Internal-Combustion Engines (forwhich we have filed application in Germany July 18, 1923), of which thefollowing is a specification.

Running internal combustionengines equipped with pistons of a lightmetal, such as aluminium, magnesium, or the like, or an alloy of any onethereof, is connected with difficulties in that it is by no means asimple matter to ensure the proper fitting-in play with consideration tothe various conditions of service of the engines, as well as to theheatefiects. fit in pistons of the kind in question in such a mannerthat they run unobjectionably at full load, but clapper and hammer atthe starting of the engine, in cold state of this latter, so strongly,that an unobjectionalole service is rendered questionable.

The object of our invention is to obviate this drawback, and we attainthat object by the improved piston illustrated by way of example in theaccompanying drawing in which Figure 1 is a side-view of this piston,Figure 2 an axialscction therethrough, Figure 3 a cross-section in theplane AA of Fig. 2, Figure 4 a cross-section in the plane BB of Fig. 4,and Figure 5 an end-view of the piston, showing its open end.

The piston consists, as regards its circun1- ferential wall, of fourparts which, although being made integrally, are distinguished from oneanother by their difierent heatconductive capacity, in that there aretwo oppositely located parts f 7 having internal projections 12 bintended to receive the piston-pin, and two oppositely located parts 9g, as shown in Figs. 2*.

The piston-wall parts 9 g are separated from the closed top of thepiston by transversely disposed slots cl d, and from the piston-wallparts by rows of holes 6 e e e. The conduction of the heat from theclosed piston-top to the wall-parts g g is, therefore, greatly impeded,whereas ,no imped- One succeeds, for instance, to

ing-means, asrega-rds the conduction of-heat, is provided between thepiston-top and the waj llqaarts f f. In the contrary, "internal ribs,such as 11,017 similar ones, may be provided just to facilitate theconduction of the heat from the piston-top to the Wall-parts f f. But asregards impeding the icofnduction from the wall-parts f f to thewallparts 9 9, there may be provided, besides the holes 6 e e e,longitudinal grooves or channels 8 s s 8 located either (as in Figs. 3and 4) internally or, if desired or preferred, externally (not shown).The ribs 2' extend from the top of the piston down to the internalprojections Z) I), as shown in Fig. 2.

Although the piston shall be practically cylindrical in transversesection. we prefer to make the diameter D (Fig. 3) just a little longerthan the diameter D, the ratio or proportion being such that thediameter D is that in which the piston fits properly into its cylinderin cold state or in only moderately heated state, whereas the otherportions of the circumferential surface of the piston will glideproperly along the corresponding portions of the inner cylinder-wallonly later on when the cylinder and the piston have attained thetemperature arising at full load of the engine. When the engine isstarted, the piston glides on the outer surfaces of its wall-parts g 7,when it will fit only partly into the cylinder, whereas it will fitproperly at its entire circumference as soon as the temperature hasrisen during the ensuing continuous running of the engine.

e claim:

1. A light-metal piston, especially for use in connection with internalcombustion-engines and having firstly, rows of holes extendingparallelly tothe axis of the piston and separating the wall-portionsconnected with the piston-pin from the other wallportions, and secondly,transverse slots separating the latter wall-portions from the closed endof the piston, substantially as set forth.

2. A light-metal piston, especially for use in connection with internalcombustion-engines, and having, firstly, rows of holes extendingparallelly to the axis of the piston and separating the wall-portionsconnected with the piston pin from the other wallportions; secondly,transverse slots separat in connection with internal combustion-engines, and having firstly, rows of holes extending parallelly to theaxis of the piston and separating the wall-portions connected with thepiston-pin from the other wallportions; secondly, transverse slotsseparating the latter wall-portions from the closed end of the piston;and thirdly, internal ribs extending from the closed piston-end to thefirst-mentioned wall-portions, substantially as set forth. a

4. A light-metal piston, especially for use in connection with internalcombustion-engines, and having firstly, rows of holes extendingparallelly to the axis of the piston and separating the wall-portionsconnected with the piston-pin from the other wall-portions; secondly,transverse slots separating the latter wall-portions from the closed endof the piston; thirdly, longitudinal grooves located between thefirst-mentioned wallportions and the other wall-portion; and fourthly,internal ribs extending from the closed piston-end to thefirst-mentioned wall-portions, substantially as set forth.

In Witness whereof we have hereunto so our hands.

PAUL 'soHt'iTTLER. STEPHAN LoFFLER.

